Effects of Different Organic Fertilizers on the Growth and YieldPerformance of Cabbage (Brassica oleracea var. capitata) Cultivated in aClosed Production System in Somalia

Abstract

Organic fertilizers offer smallholder farmers in Somalia a locally accessible alternative to costly synthetic inputs, yet little comparative evidence exists on how different organic amendments perform under the controlled, closed-system conditions increasingly used for vegetable production in the country. This study evaluated the effects of four organic fertilizers, camel manure, poultry manure, bat guano, and sesame by-products, together with an unfertilized control, on the growth and yield of cabbage (Brassica oleracea var. capitata, hybrid F1 Vizir) grown in a shade-net greenhouse in Kahda District, Mogadishu, Somalia. A randomized complete block design with five treatments and three replications was used, and plant height, shoot and root fresh and dry weights, shoot and root length, and marketable and non-marketable fresh weight were recorded at 70 days after transplanting and analyzed by analysis of variance with mean separation by least significant difference at the 5 percent level. Poultry manure and bat guano consistently produced the strongest growth and yield responses, with bat guano recording the highest plant fresh weight (1.66 kg) and shoot dry weight (161.00 g), and poultry manure producing the highest marketable fresh weight (0.97 kg), significantly exceeding camel manure and the control in most parameters. Sesame by-products performed moderately, notably producing the highest root fresh weight (64.00 g), while camel manure recorded the weakest overall performance. No significant treatment differences were found in non-marketable fresh weight. These findings indicate that poultry manure and bat guano are the most effective organic fertilizers for closed-system cabbage production under Somali conditions and support their promotion as sustainable, locally sourced alternatives to synthetic fertilizers for smallholder greenhouse horticulture.